The family Sematophyllaceae in Australia is narrowly defined to consist of 13 genera and about 36 species. Genera such as Taxithelium, Pseudohypnella and Glossadelphus are excluded. An identification key to the accepted Australian genera of Sematophyllaceae is provided. New additions to the Flora of Australia include Acroporium lamprophyllum var. percaudatum comb. & stat. nov., Clastobryurn epiphyllum, C. conspicuum, Papillidiopsis ramulina, Trichosteleum boschii and T. ruficaule. Trichosteleum elegantulunz is a new synonym of T. ruficaule. Taxa excluded from Sematophyllaceae are Acroporiunz scalarirete (= Eucamptodon scalarirete comb. nov.) and Trichosteleum inuscicolum (= Taxithelium muscicola comb. nov.). Taxithelium wattsii is transferred to Isocladiella as Isocladiella wattsii comb. nov. and Fallaciella gracilis is returned to family Lembophyllaceae.